Cool mechanic. The game is not too hard once you figured that pressing the movement key again stops you from going back.
However the tough part is getting to get the worlds to come to you when you right click. Never understood why it worked only once in a while !

Woah, interesting but difficult game. I think it's definitely that key release bug that's doing it. Sometimes the enemies send you flying, and it feels like you have no control. You may want to mention it in the main part of your entry, because it can be worked with, but releasing your input is counter-intuitive.